ci.median {statpsych}

Confidence interval for a median

Description

Computes a distribution-free confidence interval for a population median.

ci.median1 is deprecated and will soon be removed from statpsych; please switch to ci.median

Usage

ci.median(alpha, y)

ci.median1(alpha, y)

Arguments

alpha

alpha level for 1-alpha confidence

y

vector of scores

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimated median

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

Snedecor GW, Cochran WG (1989). Statistical Methods, 8th edition. ISU University Pres, Ames, Iowa.

Examples

y <- c(30, 20, 15, 10, 10, 60, 20, 25, 20, 30, 10, 5, 50, 40,
       20, 10, 0, 20, 50)
ci.median(.05, y)

# Should return:
# Estimate       SE LL UL
#       20 4.270922 10 30